Embodiments of the inventive concept relate to wireless energy receivers (receiving devices), wireless energy transmitters (transmitting devices), wireless energy transmission systems, and wireless energy transmission methods realizing efficient wireless energy transmission.
A great deal of research into wireless energy transmission using electromagnetic induction has been conducted. Yet, electrical power may be conventionally transmitted using electromagnetic induction across relatively short distances (e.g., several centimeters).
In order to overcome this limitation, a method of using magnetic resonance has been introduced. For wireless energy transmission using the magnetic resonance, LC resonance may be used and a common resonance frequency may be tuned between a transmitter/receiver pair. During this resonance frequency tuning process, the capacitance value is typically adjusted. However, it is not easy to finely adjust the capacitance value, and therefore, it is difficult to accurately perform resonance frequency tuning.
Accordingly, a better approach to resonance frequency tuning is desired that does not require direct adjustment the inductance value “L” or the capacitance value “C”.